A rotating machine typically comprises a rotatable shaft supported by one or more bearings. A shaft bearing permits rotation of the shaft while preventing or minimizing radial movements of the shaft. During operation, shaft bearings are locations within a rotating machine that are subject to high friction and therefore tend to generate a large volume of heat. Shaft bearings typically require lubrication and heat removal, functions that may be performed by flowing oil across the bearing rolling contact surfaces. Managing the flow of oil across a bearing is essential to ensuring safe and efficient operation of the rotating machine.